When I open AHI Prefs, I have a bunch of Filesave modes, and then Unit 0 that shows a couple of 16-bit modes. If I select Unit 0, there is absolutely no modes or anything... just blank.

Looks like this board is unsupported.

EDIT: And yes, all the files are in the correct place. Thanks for checking!

Try from Shell/CLI:c:DumpDebugBuffer ram:output.txt

and try to find anything it says about ENVY soundcard, in my case I have SAM460ex with SM502 soundchip and can see/read:..[_impl_InitResident] Initializing native autoinit sm502.audio V6, priority -120[_impl_OpenDevice] name is timer.device, unit 1, ior is 0x5FBC79C0SM502: Card found..

So I know my soundchip is recognized by the SM502 AHI audiodriver (maybe such output only shows with kernel.debug).